The Met used the information to track down and sack three police constables accused of leaking information about the ‘Plebgate’ incident of September 2012 in which then Government chief whip Andrew Mitchell swore at a police officer outside 10 Downing Street. This was despite the fact that the Crown Prosecution Service ruled that no charges should be brought against the officers because a jury would judge that they acted in the public interest.

Last year public authorities made more than 500,000 requests for telecommunications data under RIPA.

Both the Met Police and the Association of Chief Police Officers have said that they believe it is lawful to target journalists in this way.

But this appears to drive a cart and horses through the overriding public interest which the European Court of Human Rights has placed on the protection of confidential journalistic sources under Article 10 (freedom of expression).

Put simply, if police and other public authorities can secretly obtain journalists’ phone records at will – why would any public sector whistleblower ever contact a journalist by telephone again?

This is seriously bad news for anyone who believes that scandals and corruption are best dealt with by being exposed.

Press Gazette has launched the Save Our Sources campaign with a first simple and achievable goal.

We have addressed our petition to the Interception of Communications Commissioner (who oversees the use of RIPA) calling on him to take urgent action to ensure that RIPA is not used by public authorities to identify journalists’ confidential sources. But we also be using it to lobby the Home Office, the Director of Public Prosecutions and any other relevant public figures.

We believe this issue could be addressed by modifying the guidelines issued to public authorities. It could also be that the Director of Public Prosecutions has a role to play by clarifying the law on public sector whistleblowers – and explaining why it is not in the public interest to prosecute them.

RIPA requests can only be used to detect and expose criminality, so surely the threshold at which merely talking to a journalist becomes a criminal matter must be a high one?

It may be that a change in the law is needed to RIPA setting out the public interest in protecting the confidentiality of journalistic sources.

There will be cases when the public interest in handing over confidential journalistic material outweighs the public interest in keeping such information secret.

But Press Gazette believes that such decisions are best handled via the courts, with requests for journalistic material made via the Police and Criminal Evidence Act (which allows journalists to make representations and argue their case).